Combination alarm and filter bypass device for a suction cleaner

ABSTRACT

A combined alarm and filter bypass device for use with a suction cleaner wherein the device is compact in size and of a simplified construction. The housing of the device is of a shallow, generally box-like configuration which permits the device to be installed in various locations in or on the casing of an associated cleaner and which facilitates the visibility thereof from the exterior of the casing. The reduced size of the device also minimizes interference with other components of the cleaner.

United States Patent Kinsella [54] COMBINATION ALARM AND FILTER BYPASS DEVICE FOR A SUCTION CLEANER [72] Inventor: DanlelJ.Kinsella,Bloomington,l1l.

[73] Assignee: National Union Electric Corporation,

Greenwich, Conn.

[22] Filed: May 28,1971

[21] Appl.No.: 147,837

[451 July 25,1972

Primary Examiner-Louis J. Capozi AttorneyHibben, Noyes & Bicknell [57] ABSTRACT A combined alarm and filter bypass device for use with a suc tion cleaner wherein the device is compact in size and of a simplified construction. The housing of the device is of a shallow, generally box-like configuration which permits the device [52] [1.8. CI I 16/1 14 AD, 15/339, 1 16/70 to be installed in various locations in or on the casing of an as- [51] Int. Cl. ..G01d 21/00 sociated cleaner and which facilitates the visibility thereof [58] Field of Search ..l 16/ 70, l 14 AD, 1 17; 210/90, from the exterior of the casing. The reduced size of the device 210/87; 15/339 also minimizes interference with other components of the cleaner.

[56] memes C'ted 14 Claims, 8 Drawing Figures UNITED STATES PATENTS 3,119,369 1/1964 Harland et a1. ..116/114 'I I g; Mar-i=3- mC/v/ e0 Patented July 25, 1972 T AVAILABLE COPY 3,678,882

2 Sheets-Sheet 1 z; a 111; I III] .II r m -1/. M1 I 17 1842592151.:

Patented July 25, 1972 B351 EO PY- 3,678,882

2 Sheets-Sheet 2 COMBINATION ALARM AND FILTER BYPASS DEVICE FOR A SUCTION CLEANER This invention relates to an alarm device for indicating the degree of clogging of the filter of a suction cleaner, and more particularly to a combination alarm and filter bypass device for a suction cleaner, said device being of compact size and simplified construction.

Various types of alarm or signal devices have been hereto fore advanced for indicating the degree of clogging of the filter of canister-type suction cleaners. Some of such devices are effective to emit either a visual or audible signal, or both, to indicate the degree of clogging of the filter. Moreover, some of the devices of the aforementioned type provide a continuous visual signal of the degree of clogging of the associated filter and a subsequent audible signal when the filter reaches a predetermined degree of clogging. Examples of devices of this character are disclosed in the Schaefer et al U.S. Pat. No. 3,381,652 and Harland et al US. Pat. No. 3,l 19,369.

While most of the alarm or signal devices heretofore advanced have proved generally satisfactory for their intended purpose, many of them have sufiered from the disadvantages of comparatively large size and complex construction. As a result of such large size, it was frequently necessary to provide special mounting bosses or recesses in or on the associated cleaners to receive the devices. Consequently, the overall size of the cleaners was increased. The aforementioned complex construction of many of such devices further rendered them disadvantageous from the standpoint that they were less reliable in operation and more costly to manufacture.

Accordingly, it is a general object of the present invention to provide a novel and improved alarm device for indicating the extent of clogging of the filter of a suction cleaner, which overcomes the aforementioned disadvantages of the prior art.

Another object is to provide a novel combination alarm device of the foregoing character which is of compact size and simplified construction.

A more particular object is to provide a novel alarm device for indicating the degree of clogging of the filter of a suction cleaner having a casing, wherein the position of a piston in a housing is utilized as a signal to indicate the degree of clogging of the filter and wherein the housing is of a shallow, box-like form to facilitate observation of the position of the piston in the housing from the exterior of the casing.

A further object is to provide a novel alarm device of the character described, which may be rapidly and easily assembled, which utilizes a minimum number of parts, and which is economical to manufacture.

Other objects and advantages of the invention will become apparent from the following detailed description and accompanying sheets of drawings, in which:

FIG. 1 is a side elevational view, with portions broken away to show internal structural details, of a canister-type suction cleaner incorporating an alarm device embodying the features of the present invention;

FIG. 2 is an enlarged, fragmentary top plan view of a portion of the cleaner illustrated in FIG. I and showing in full and broken lines the position of the alarm in the cleaner;

FIG. 3 is a transverse sectional view taken along the line 3- 3 of FIG. 2;

FIG. 4 is a transverse sectional view taken along the line 4 4 of FIG. 3;

FIG. Sis a top plan view of the alarm device of FIG. 3;

FIG. 6 is a bottom plan view ofthe device shown in FIG. 3;

FIG. 7 is an elevational view of the left or inlet end of the device shown in FIGS. and 6; and

FIG. 8 is a perspective view of the device of FIG. 5, with arrows showing the direction of the flow of air therethrough.

In FIG. 1, a canistertype suction cleaner 10 is illustrated. Such cleaner is exemplary of one type of suction cleaner with which the alarm device of the present invention is adapted for use. The cleaner 10, in the present instance, comprises a casing I I which includes a lower casing portion or shell 12 and an upper casing portion or cover 13 hinged to the lower portion 12 at right end thereof as viewed in FIG. I. A pair of wheels 14, only one of which is shown in FIG. I, may be provided at the right end of the lower casing portion 12 as viewed in FIG. I, and a single castering wheel 16 maybe provided at the left end of the lower casing portion 12 as viewed in FIG. I to facilitate movement of the cleaner. A carrying handle 17 is also provided at the left end of the cover 13, as viewed in F IG. 1.

Suction generating means in the form of a motor-fan unit 20 is shown in broken lines and mounted in the interior of the casing 11. Such unit includes a motor portion 22 and a fan portion 23 driven by the motor portion 22. A fan (not shown) in the fan portion 23 draws air from the interior of the casing ll through an inlet (also not shown) in the upper end of the fan portion, and discharges such air through passages (also not shown) in the casing 11 through an exhaust outlet 24 in the right end wall of the lower casing portion 12, as viewed in FIG. I. The exhaust outlet 24 is isolated from the inlet of the fan portion 23 by a partition or false bottom (not shown) in the lower casing section 12.

Air containing dirt or other foreign particles enters the casing 11 through a hose (not shown) having one end connected to an inlet opening 26 in the cover 13. The inlet opening 26 is adapted to receive a connector fitting (not shown) secured to one end of a flexible hose (also not shown), the other end of the hose being adapted to receive various accessory cleaning tools.

After passing through the inlet 26, the flow of air containing dirt and other foreign particles enters a filter 28 connected to the inlet 26. The filter 28, in the present instance, is in the form of a porous paper bag having a cardboard mounting collar 29 surrounding an opening in the bag and adapted to engage an annular resilient seal 32 surrounding the inlet opening 26 and carried by the cover 13.

As the contaminated flow of air passes through the filter 28, dirt and other foreign particles are retained in the filter so that substantially clean air is discharged through the walls of the filter to the interior of the casing 11. Such cleaned air enters the inlet of the fan portion 23 of the motor-fan unit 20 and is thereafter discharged through the exhaust outlet 24 as previously described. Operation of the motor-fan unit 20, and consequently the cleaner 10, is controlled by a switch actuated by a foot-operated lever or treadle 32 mounted on the lower left end ofthe cleaner casing 11, as viewed in FIG. I.

From the foregoing it will be apparent that as the cleaner [0 is used, the filter 28 will fill with dirt or other foreign particles. Consequently, less air will pass through the filter to the interior of the casing 11, and the pressure in the casing II and on the outer or downstream side of the filter 28 will decrease. Since reduction in the flow of clean air through the filter 28 also results in a similar reduction in the flow of air entering the inlet 26, the efficiency of the cleaner will gradually decrease. Moreover, as the flow of air through the filter 28 decreases with increased clogging of the filter, the operating temperature of the motor-fan unit 20 would normally increase with the resulting likelihood of damage to or burn out of the motor thereof if the cleaner were operated for any length of time with a substantially fully clogged filter. In order to prevent such damage from occurring and also to alert the user of the cleaner to the condition of the filter 28, the cleaner l0 includes an alarm and filter bypass device 40 embodying the features of the present invention. The alarm device 40, in the present instance, is mounted in a recess or cavity 41 (FIG. 3) in the upper surface of a supplemental casing 42 secured to the upper surface of the cover 13 by fasteners, not shown. The supplemental casing 42 also serves as a mounting for additional controls for the operation of the cleaner 10.

Referring now to FIGS. 3-8, inclusive, in conjunction with FIGS. 1 and 2, the alarm device 40 comprises an elongated body or housing 43 of a shallow, generally box-like form and having longitudinally spaced end walls 44 and 45, laterally spaced side walls 46 and 47, and top and bottom walls 48 and 49, respectively. An inlet opening or port 52 is provided at the outer end of a generally cylindrical extension 53 on the end wall 44, and an outlet opening or port 54 (FIGS. 3, 4 and 5) is provided in a generally rectangular boss 56 which depends from the bottom wall 49 adjacent the end wall 45. When the device 40 is mounted in'its recess 41 in the supplemental casing 42, the lower end of the boss 56 engages a gasket 57 (FIG. 3) which serves to prevent leakage of air between the outlet opening 54 and the interior of the casing 11. Another opening 58 in the top wall, indicated at 59, of the cover 13 provides communication between the opening 54 and the interior of the casing 11. Air from the exterior of the casing 11 is communicated to the inlet opening 52 of the device 40 through slots 60 (FIGS. 2 and 3) in the side walls of the supplemental casing 42. Laterally extending lugs 61 on bottom wall 49 of the housing 43 serve to locate and prevent movement of the device 40 in the recess 41.

A shiftable member in the form of a piston 61 having a generally box-like shape is mounted in the housing 43 for movement therein. The piston 61 has a top wall 62 as viewed in FIG. 3, side walls 63 and 64 (FIGS. 4 and 5) and end wall 65 (FIGS. 3 and 4) at the right end thereof as viewed in FIG. 3. The piston 62 has no bottom wall, and the left end thereof, as seen in FIG. 3 and indicated at 66, is substantially open, except for the provision of a pair of, strengthening gussets 67 (FIG. 4) which extend between the side walls 63 and 64 and top wall 62 at the end 66. The gussets 67 prevent flaring or divergence of the side walls 63 and 64 of the piston after molding, and consequently reduce any tendency of the piston 61 to bind in the housing 43 after the device 40 has been assembled.

The outer surface of the side walls 63 and 64 are spaced from the inner surface of the walls 46 and 47 of the housing 43, and the outer surface of the top wall 62 of the piston is likewise spaced from the inner surface of the top wall 48 of the housingv Consequently, the clearance spaces, indicated at 50 in FIGS. 3 and 5, are provided between the respective walls, except for a pair of outwardly projecting ribs 68 and 69 (FIGS. 3 and 5) at the left and right ends, respectively, ofthe piston as veiwed in FIGS. 3 and 5. The ribs 68 and 69 closely fit the interior of the housing 43 and, because of their relatively small area, minimize sliding friction between the piston 61 and surrounding walls of the housing 43 during movement of the piston.

The piston 61 is biased toward the left or inlet end of the housing 43 by spring means in the form of a coil spring 70. One end, indicated at 71 in FIG. 3, of the spring 70 is con nected to retaining means in the form of a post 72 carried on the piston 61, The post 72, in the present instance, depends from the underside of the top wall 62 of the piston 61 adjacent the end wall 65 thereof. The opposite end, indicated at 73, of the spring 70 engages another retaining means in the form of a post 74 which depends from the underside of the top wall 48 of the housing 43, adjacent the end wall 44 thereof. The spring 70 normally maintains the left end 66 ofthe piston 61 engaged with stop means in the housing 43. Such stop means, in the present instance, comprises a pair of cylindrical detents 76 and 77 which depend from the undersurface of the top wall 48 of the housing 43. The detents 76 and 77 maintain a slight preload or tension in the spring 70 to prevent rattling of the piston 62 in the housing 43.

The length and rating of the spring 70 is such as to maintain the piston 61 in the full line position thereof illustrated in FIG. 3 when the cleaner is operating with a new or substantially unclogged filter, and to permit the piston 61 to move to the fragmentary broken line position thereof illustrated in FIG. 3 and indicated at 61' when the filter 28 reaches a predetermined or dangerous degree of clogging. When in the latter position, the end wall 65 of the piston will have moved over the outlet opening 54 and thus established communication between the opening 54 and the inlet 52 through an air passage means through the device 40. Such air passage means includes the inlet port 52, the walls 46-49 of the housing 43 upstream from the piston, and a cavity 76 (FIG. 3) provided by the interior of the piston 61 and the adjacent bottom wall 49 of the housing 43. The direction of the flow of air entering and leaving the housing 43 is indicated by the arrows 77 and 78 in FIG. 7, respectively.

While substantially all of the flow of air through the housing 43 passes through the cavity 76 of the piston 61 when the latter occupies its broken line position indicated at 61 a small quantity of air will at all times fiow through the housing 43 and around the exterior of the piston 61, due to the fact that the ribs 68 and 69 do not tightly fit the interior of the housing 43 and there are clearance spaces 50 between the major portion of the piston and the surrounding walls of the housing 43.

In order to permit observation of the position of the piston 61 in the housing 43 from the exterior of the supplemental casing 42, at least a portion of the top wall 48 of the housing 43 is of a transparent material, such as polystyrene plastic, and the piston 61 is of an opaque material, such as colored Delrin. In this regard, since the major portion of the housing 43 is covered by a plate 81 when the device 40 is installed in the supplemental casing 42, the top wall 48 of the housing 43 is provided with an upraised rectangular portion 82 which extends through an opening 83 (FIGS. 2 and 3) in the plate 81. Thus, when the device 40 is mounted in its receiving cavity 41 in the supplemental casing 42 and covered by the plate 81, the position of the piston 61 in its housing 43 may be easily observed through the upraised transparent portion 82 of the housing 43, thereby providing a progressive visual signal of the degree of clogging of the filter 28. The portion of the piston 61 visible through the transparent portion 82 of the housing 43 thus comprises means providing a visual signal proportional to the degree of clogging of the filter 28.

As heretofore mentioned, when the piston 61 reaches its fragmentary broken line position 61 in the housing 43, the air passage through the housing 43 will no longer be restricted by the piston and consequently the flow of air through the device 40 to the interior of the casing 11 will substantially increase. Such increased flow serves the dual function of providing an audible signal to the user of the cleaner indicative of the fact that the filter 28 has reached a dangerously clogged condition, and also to prevent overheating of the motor 22 of the motorfan unit 20.

The aforementioned audible signal is provided by sound generating means in the form of a whistle mounted in the cylindrical extension 53 of the housing 43. Such whistle, in the present instance, comprises the inlet opening 52, which is substantially circular, and another axially aligned, circular opening 86 at the inner end of the cylindrical portion 53. An axially outwardly extending projection 87 is provided on the end face of the cylindrical portion 53, the projection 87 having a horizontal edge portion 88 which, as seen in FIG. 7, partially overlaps the upper margin of the opening 52. The overlapping horizontal edge portion 88 is efiective to change the pitch of the whistle 52,86 so that the sound emitted therefrom is more clearly differentiated from the other sounds emitted from the cleaner when the latter is in operation.

Thus, when the quantity of air flowing through the housing 43 increases because of movement of the piston to its broken line position 61, an audible signal will be emitted by the device 40. Consequently, the user of the cleaner 10 will receive both an audible and visual signal indicative of the fact that the filter bag 28 has become dangerously clogged and in need of replacement.

At the same'time that the device 40 is emitting an audible signal, the increased flow of air through the housing 43 will bypass the filter 28 and flow directly to the motor-fan unit 20 to cool the motor thereof. Thus, damage to the motor from overheating is avoided.

While the device 40 has herein been described as being operable to provide both a visual and audible signal indicative of the degree of clogging of the filter bag 28, it will be understood that the device 40 could be constructed or rendered effective to provide only one of such signals. In other words, it is within the contemplation of the present invention to provide a combination alarm and filter bypass device for a suction cleaner, which will provide only a visual or audible signal. It will further be understood that modifications and variations of the invention may be effected without departing from the concepts thereof as set forth in the appended claims.

I claim:

1. A combination alarm and filter bypass device adapted for use with a suction cleaner including a casing having an air inlet, an air outlet, a filter operably disposed between said inlet and outlet, and suction means for generating a zone of negative pressure in said casing downstream from said filter and inducing a flow of air into said inlet through said filter and out of said outlet, said device comprising a housing adapted to be mounted on said cleaner casing and having an air inlet port therein communicating with the exterior of said casing, an air outlet port spaced from said inlet port and adapted to communicate with said negative pressure zone, and air passage means extending between said inlet and outlet ports, a member shiftably mounted in said housing and movable therein in response to a differential pressure between said inlet and outlet ports, said shiftable member having spaced ends respectively facing said inlet and outlet ports and a cavity therein comprising a portion of said air passage means, the end of said shiftable member facing said inlet port having an opening therein providing communication between said inlet port and said cavity, and means responsive to movement of said shiftable member in said housing providing a signal indicative of the degree of clogging of said filter, said shiftable member also establishing an increased air flow through said passage means and bypassing said filter upon movement of said shiftable member beyond a predetermined position in said housing.

2. The device of claim 1, further characterized in that said last mentioned means includes a portion of said shiftable member visible through said housing and providing a visual signal proportional to the degree of clogging of said filter.

3. The device of claim 1, further characterized in that said last mentioned means includes sound generating means communicating with said air passage means, said sound generating means being operable to emit an audible signal in response to movement of said shiftable member beyond said predetermined position in said housing and the establishment of said increased air flow through said air passage means.

4. The device of claim 1, further characterized in that said housing has spaced end walls and connecting side walls, said inlet port is provided in one of said end walls, and said outlet port is provided in one of said side walls adjacent to the other ofsaid end walls.

5. The device of claim 4, further characterized in that the end of said shiftable member facing said outlet port is closed, and said closed end of said shiftable member moves over said outlet port and connects the latter with said cavity to provide said increased air flow through said passage means when said shiftable member shifts to said predetermined position.

6. The device of claim 1, further characterized in that spring means is provided for urging said shiftable member toward said inlet port, whereby the position of said shiftable member in said housing is proportional to the pressure differential between said inlet and outlet ports.

7, The device of claim 6, further characterized in that said housing includes first retaining means for receiving and retaining one end of said spring means, and said shiftable member includes second retaining means for receiving and retaining the opposite end of said spring means, said second retaining means extending into said cavity.

8. The device of claim 7, further characterized in that said first retaining means comprises a post carried by said housing adjacent to said inlet port, said second retaining means comprises another post carried by said shiftable member adjacent to the end thereof facing said outlet port, and said spring means comprises a coil spring having its ends respectively engaged with said posts.

9. The device of claim 6, further characterized in that said housing includes stop means for limiting movement of said shiftable member toward said inlet port and for maintaining a predetermined preload in said spring means,

10. The device of claim 9, further characterized in that said stop means comprises a detent carried on the inner surface of one of the side walls of said housing and disposed in the path of movement of said shiftable member.

1 1. An alarm device adapted for use with suction cleaner including a casing having an inlet, an outlet, a filter operatively disposed between said inlet and outlet, and means for inducing a flow of air into said inlet, through said filter and out of said outlet, said device comprising a shallow, generally box-like housing of compact size and having a transparent portion, and a member shiftably mounted in said housing and movable relative to said transparent portion to provide a signal indicative of the degree of clogging of said filter, whereby the shallow, box-like form and compact size of said housing permits said device to be mounted in various locations in or on said casing without increasing the size of said casing and also facilitates observation of the position of said shiftable member in said housing from the exterior of said casing.

12. The device of claim ll, further characterized in that said shiftable member comprises a generally rectangularlyshaped piston.

13. The device of claim 12, further characterized in that said housing is elongated and has top, bottom, side, and end walls, an air inlet port is provided in one of said end walls, an air outlet port is provided in said bottom wall adjacent the other of said end walls, and said piston is elongated and has at least one side wall and only one complete end wall.

14. The device of claim 13, further characterized in that said piston has a pair of spaced side walls and a top wall. 

1. A combination alarm and filter bypass device adapted for use with a suction cleaner including a casing having an air inlet, an air outlet, a filter operably disposed between said inlet and outlet, and suction means for generating a zone of negative pressure in said casing downstream from said filter and inducing a flow of air into said inlet through said filter and out of said outlet, said device comprising a housing adapted to be mounted on said cleaner casing and having an air inlet port therein communicating with the exterior of said casing, an air outlet port spaced from said inlet port and adapted to communicate with said negative pressure zone, and air passage means extending between said inlet and outlet ports, a member shiftably mounted in said housing and movable therein in response to a differential pressure between said inlet and outlet ports, said shiftable member having spaced ends respectively facing said inlet and outlet ports and a cavity therein comprising a portion of said air passage means, the end of said shiftable member facing said inlet port having an opening therein providing communication between said inlet port and said cavity, and means responsive to movement of said shiftable member in said housing providing a signal indicative of the degree of clogging of said filter, said shiftable member also establishing an increased air flow through said passage means and bypassing said filter upon movement of said shiftable member beyond a predeteRmined position in said housing.
 2. The device of claim 1, further characterized in that said last mentioned means includes a portion of said shiftable member visible through said housing and providing a visual signal proportional to the degree of clogging of said filter.
 3. The device of claim 1, further characterized in that said last mentioned means includes sound generating means communicating with said air passage means, said sound generating means being operable to emit an audible signal in response to movement of said shiftable member beyond said predetermined position in said housing and the establishment of said increased air flow through said air passage means.
 4. The device of claim 1, further characterized in that said housing has spaced end walls and connecting side walls, said inlet port is provided in one of said end walls, and said outlet port is provided in one of said side walls adjacent to the other of said end walls.
 5. The device of claim 4, further characterized in that the end of said shiftable member facing said outlet port is closed, and said closed end of said shiftable member moves over said outlet port and connects the latter with said cavity to provide said increased air flow through said passage means when said shiftable member shifts to said predetermined position.
 6. The device of claim 1, further characterized in that spring means is provided for urging said shiftable member toward said inlet port, whereby the position of said shiftable member in said housing is proportional to the pressure differential between said inlet and outlet ports.
 7. The device of claim 6, further characterized in that said housing includes first retaining means for receiving and retaining one end of said spring means, and said shiftable member includes second retaining means for receiving and retaining the opposite end of said spring means, said second retaining means extending into said cavity.
 8. The device of claim 7, further characterized in that said first retaining means comprises a post carried by said housing adjacent to said inlet port, said second retaining means comprises another post carried by said shiftable member adjacent to the end thereof facing said outlet port, and said spring means comprises a coil spring having its ends respectively engaged with said posts.
 9. The device of claim 6, further characterized in that said housing includes stop means for limiting movement of said shiftable member toward said inlet port and for maintaining a predetermined preload in said spring means.
 10. The device of claim 9, further characterized in that said stop means comprises a detent carried on the inner surface of one of the side walls of said housing and disposed in the path of movement of said shiftable member.
 11. An alarm device adapted for use with suction cleaner including a casing having an inlet, an outlet, a filter operatively disposed between said inlet and outlet, and means for inducing a flow of air into said inlet, through said filter and out of said outlet, said device comprising a shallow, generally box-like housing of compact size and having a transparent portion, and a member shiftably mounted in said housing and movable relative to said transparent portion to provide a signal indicative of the degree of clogging of said filter, whereby the shallow, box-like form and compact size of said housing permits said device to be mounted in various locations in or on said casing without increasing the size of said casing and also facilitates observation of the position of said shiftable member in said housing from the exterior of said casing.
 12. The device of claim 11, further characterized in that said shiftable member comprises a generally rectangularly-shaped piston.
 13. The device of claim 12, further characterized in that said housing is elongated and has top, bottom, side, and end walls, an air inlet port is provided in one of said end walls, an air outlet port is provided in said bottom wall adjacent the otheR of said end walls, and said piston is elongated and has at least one side wall and only one complete end wall.
 14. The device of claim 13, further characterized in that said piston has a pair of spaced side walls and a top wall. 